Methods for the reduction of moisture variability in large cheese blocks

ABSTRACT

The present invention is directed to processes for making blocks of cheese having reduced moisture variability using controlled cooling of cheese curd to form the final cheese blocks.

RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.11/087,981, filed on Mar. 23, 2005, now U.S. Pat. No. 7,560,129, whichis hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to cheese manufacture and moreparticularly it relates to processes for the production of large sizedblocks or barrels of cheese having reduced moisture variability withinthe blocks or barrels. The processes of this invention use controlledcooling to provide the reduced moisture variability within the block orbarrel of cheese.

BACKGROUND OF THE INVENTION

Natural cheese of the American type (e.g., Cheddar, Monterey Jack, orColby) is manufactured by coagulating ripened milk of proper aciditywith rennet, cutting the coagulant, and cooking the resulting curd,whereupon the curd is pressed and further whey removal is effected. Thedesired flavor, aroma, and texture of the cheese is obtained by curingwhich involves holding the cheese for a time at desired temperatures.

The moisture content of hard cheeses is important as it impacts thetexture of the product. The fat content of hard cheeses is important asit significantly influences the sensory properties thereof by aiding theproduction of flavor, aroma, and body in cured cheese. The minimum milkfat and maximum moisture content of most cheeses is regulated by Federaland state regulations. For example, in the United States, hard cheddarcheese should have a minimum milk fat content of 50 percent by weight ofthe solids, and a maximum moisture content of 39 percent by weight.However, reduced fat and low fat cheeses are desired by many consumers,which typically have lower fat content and higher moisture content thanthe standard hard cheeses. In order to comply with U.S. Standards ofidentity applicable to reduced fat cheddar cheeses, for instance,cheddar cheese may be manufactured to contain approximately 33 percentless fat and up to approximately 20 percent more moisture than standardcheddar cheese.

Natural cheeses, including reduced fat natural cheeses, have beenproduced in a variety of unit sizes. In cheese production, however, itis desirable to produce large rectangular blocks of cheese which, forexample, may weigh greater than about 500 pounds (and typically about640 pounds). These large blocks of cheese can be conveniently dividedinto smaller blocks or shredded, and packaged for retail. Inconventional production of such large blocks of cheese, cheese curd isseparated from free whey, and then the drained curd is placed in a bulkcontainer for pressing. In the instance of cheese blocks, the containeris provided with openings through which the whey drains as the curd ispressed. This procedure is varied somewhat for the manufacture of cheesebarrels, in which the cheese curd may be sealed prior to and duringpressing. Generally, such cheese blocks or barrels may be made using asingle block fill method or apparatus or a block forming tower method orapparatus.

It is common practice in the manufacture of cheddar and like types ofcheese to cool the large pressed blocks of cheese from the manufacturingtemperature of about 85-90° F. to a refrigerated temperature of about32-40° F. Such large blocks of cheese take multiple days to cool fromthe manufacturing temperature of 85-90° F. to the cold room temperatureof about 32-40° F. The cheese is then stored under conditions and for aperiod of time conducive for curing the cheese.

In the making of large cheese blocks, it is desirable that the moisturecontent be uniform throughout the block. In prior cheese manufacture,however, a moisture gradient has been observed to occur in the cheeseblocks during the cooling period. Moisture has tended to migrate fromthe core or central region of the cheese blocks towards the exteriorsurfaces. For instance, over the first several days as cheese cools inbulk containers, moisture is drawn from the warmer interior of the blockor barrel to their cooler exterior. For example, single 640 pound blocksof reduced fat cheddar commonly have been observed having an interiormoisture of about 44 percent and an external moisture of about 49percent. The moisture gradient makes it more difficult to form a cheeseblock having uniform texture throughout. The exterior surface regions ofthe cheese block may have a firm, smooth texture while the core orcentral portions of these cheeses may be crumbly or cracked, leading toinferior or waste portions. When the cheese is converted to retailpieces (e.g., 8 oz. chunk or shreds), it is difficult to deal with boththe dry center portions and the very moist edges. From a consumer'sperspective, cheese from the center often is perceived differently fromthat at the edge, and the latter variety is preferred by the consumersfrom an organoleptic standpoint. Moreover, when manufacturing reducedfat cheese or high moisture dry salted cheeses, high moisture targetlevels may be difficult to achieve without the excessive use of coldwash water. The addition of wash water creates a problem for downstreamwhey processing and waste water treatment, which is relatively costly.

It has been proposed to rest the cheese blocks at the manufacturingtemperature for a period of time before cooling them to permit them toequilibrate. However, in reduced fat (higher moisture) content cheesesin particular, resting the cheese after manufacture and prior tocooling, may lead to increased microbial loads in the finished foodproduct.

It also has been known to accomplish the draining and the pressing ofthe curd with round probes inserted in the curd to assist in thedraining of the whey. However, after removal of these round probes, softwhite spots have been left in the curd mass where the curd did not fusesatisfactorily, and moisture variations from point to point within theblock have been greater than desired. Various treatments of the curdblocks prior to and during curing have not overcome the problem. It hasalso been known to use a generally V-shaped perforated pressure plate inconnection with the pressing of the curd, as shown in U.S. Pat. No.3,404,009. However, this pressure plate was primarily designed to removeair and is not adapted for the manufacture of large blocks of cheese.Blocks of cheese also have been rotated during curing in an effort toreduce the occurrence of moisture gradients. Such block rotationprocedures are labor intensive and add to the manufacturing costs.

There remains a need for new approaches that will provide an improvedprocess for manufacturing large blocks of cheese, such as reduced fathigher moisture cheeses, with more uniform distribution of moisture andtexture throughout the cheese block and which reduce the use of excesswater. The present invention provides such processes.

SUMMARY OF THE INVENTION

The present invention is directed to processes for making large blocksor barrels of cheese having reduced moisture variability through itsthickness. For purposes of this invention, a “large block” of cheese isintended to include three dimensional blocks or other shapes (includingbarrels) having minimum weight of at least about 500 pounds. It has nowbeen found that it is possible to reduce moisture variability throughoutsuch large blocks by controlled cooling of the blocks. Generally, themoisture content of large blocks or barrels of cheese produced by thepresent methods will vary by about 2 percent or less (generally asmeasured from near the center of the block or barrel to a location nearone of the edges).

In a first major embodiment (i.e., the so-called “injection method”),controlled cooling is carried out by effectively and rapidly cooling amiddle or central portion of the cheese block (or multiple portionslocated throughout the cheese block) prior to cooling the entire block.In a second major embodiment (i.e., the so-called “intermediatetemperature method”) a cheese block at an initial temperature of about60 to 90° F. is placed in an intermediate temperature cooling room(i.e., temperature of about 10 to 40° F. below the initial temperaturebut at least about 10° F. above the temperature of a final cooling room)for about 2 to 5 days and then transferred to the final cooling room(i.e., temperature of about 35 to about 45° F.) for about 5 to 8 days.

In the injection method, a number of methods can be used to provide thisinitial cooling effect. Such methods can include, for example,introducing chilled brine solution, precooled curd material, ormechanical cooling device (e.g., a tube or plate having circulatingcoolant) into the middle or central portion of the block or intomultiple portions of the block. Generally, the central portion (ormultiple portions) of the cheese block is (are) cooled to about 10 toabout 45° F., and preferably to about 20 to about 45° F., below theinitial temperature of the cheese block (typically about 80 to about 90°F. but can be as low as about 60° F.) prior to the cooling of the cheeseblock. Generally the initial cooling is carried out immediately beforethe cheese block is placed in a conventional cooling room.

Although other methods can be used to provide the initial coolingeffect, this injection method will be described using the chilled brinesolution method. The other methods can easily be employed using theguidance, appropriately modified, provided using the chilled brinesolution method.

In injection method using a central injection site only, a form or bulkcontainer having a bottom and sidewalls, and a tube having a fill endand an sectional opposite discharge end, are provided. The tube isvertically positioned at an approximately central axial location of thecontainer such that the discharge end of tube is at or near the bottomof the container. Cheese curd is introduced into the container, and thetube via its fill end. Then, chilled brine is introduced into the tubevia its fill end to mix with curd therein. The tube is removed from thecheese curd in the container. The cheese curd is pressed into a curdmass, and then cooled, and thereafter cured, providing a cheese blockhaving reduced moisture variability.

In one preferred embodiment using the injection method, the tube ispositioned in the container with its discharge end resting on the bottomof the container or in close proximity thereto (i.e., generally with thedischarge end within about 8 inches and preferably within about 2 inchesof the bottom). Preferably, the discharge end of the tube rest on thebottom of the container. After filling with the chilled brine solution,the tube preferably is removed from the cheese curd by raising the tube,approximately vertically, out of the container, in order to help ensurethat the brine solution is introduced in the central axial region of thecheese curd mass. Preferably, the chilled brine has a salt content whichapproximately matches the salt content of the moisture phase of thecheese curd.

Generally the cross sectional area of the central tube used in theinjection method is about 2.5 to about 25 percent and more preferablyabout 5 to about 20 percent of the total cross sectional area of theblock. The tube may comprise a cross-sectional diameter of about 7inches to about 9 inches. Where more than one tube is used, the tubesmay, of course, have smaller diameters. The tube may comprise a unitaryself-supporting hollow member comprised of a wall material selected fromthe group consisting of polymer, metal, ceramic, and wood. Although thetube preferably has a circular cross section, tubes have other crosssections (e.g., square, rectangular, oval, and the like) can be used.More than one tube can be used so long as the cooling of the centralportions is effective. The brine solution preferably is introduced intothe tube positioned within the container as a salt solution at about 25to about 30° F. having a salt content which is approximately the same asthe salt content in the moisture phase of the cheese curd. In oneparticular embodiment, the cheese curd has a salt content of about 4 toabout 6 percent into which the brine solution is introduced as about 4to about 6 percent salt solution at about 25 to about 30° F., and moreparticularly as about 4.5 to about 5.5 percent salt solution at about 25to about 27° F. In one preferred embodiment, the brine solution isintroduced into the tube at a rate of about 10 to about 25 pounds of theabout 4 to about 6 percent brine solution per 640 pounds of cheese curd,and more preferably about 12 to about 15 pounds of the 4-6 percent brinesolution per 640 pounds of cheese curd. Comparable rates for other sizedcheese blocks can be used.

In the second major embodiment (i.e., intermediate temperature method),controlled cooling is effected by providing an intermediate temperaturecooling room (i.e., temperature between that of the initial filltemperature and the final cooling room). This method comprises providinga bulk container having a bottom and sidewalls; introducing cheese curdhaving an initial temperature into the container; pressing the cheesecurd to form a cheese block; cooling the pressed cheese block at anintermediate temperature to form a partially cooled cheese block for afirst cooling period; cooling and curing the partially cooled cheesebock at a final temperature and for a second cooling period, therebyproviding a final cheese block having reduced moisture content variationbetween a geometric center and side edges thereof; wherein the cheeseblock has a weight of at least about 500 pounds; wherein the initialtemperature is about 60 to about 90° F., wherein the intermediatetemperature is about 10 to about 40° F. below the initial temperatureand at least about 10° F. above the final temperature, wherein the finaltemperature is about 35 to about 45° F., wherein the first coolingperiod is about 2 to about 5 days, wherein the second cooling period isabout 5 to about 8 days, and wherein the first and the second coolingperiods are sufficient to cool the final cheese block to less than about45° F.

In this intermediate temperature method, the formed cheese blocks havingan initial temperature (i.e., the fill temperature at which the initialcheese blocks are formed) are placed in an intermediate temperaturecooling room for about 2 to about 5 days before being placed in a finaltemperature cooling room for the remainder of the cooling period (i.e.,a second cooling period). Generally the length of total cooling period(i.e., the sum of the first and second cooling periods) is about 8 toabout 12 days; it should be sufficient to cool the cheese block to belowabout 45° F. The initial temperature (T_(inital)) is higher than theintermediate temperature (T_(intermediate)) which is higher than thefinal temperature (T_(final)); in other words,T_(inital)>T_(intermediate)>T_(final).

Generally in the controlled temperature processes of this invention, thecheese curd is pressed into a cheese mass having a diameter of about 24to about 30 inches, which upon cooling using the processes disclosedherein, has significantly reduced moisture variability between alocation at a geometric center and a side edge portion thereof. Theabsolute value of this reduced moisture variability will depend, atleast in part, on the initial temperature of the filled cheese curd.Generally, the lower the initial temperature of the cheese curd, thelower the absolute value of the reduced moisture variability. Forexample, if the cheese curd has an initial temperature of about 60° F.,the moisture content is expected to vary by about 1 percent or less (andpreferably less than about 0.5 percent) from a location at a geometriccenter and a side edge portion. If the cheese curd has an initialtemperature of about 90° F., the moisture content is expected to vary byabout 2 percent or less (and preferably less than about 1.25 percent)from a location at a geometric center and a side edge portion.Regardless of the initial temperature of the cheese curd, cheese blockproducts made by the processes of this invention have reduced moisturevariability as well as improved uniformity in texture and/or othersensory properties between the central and side portions of the cheeseblock products as compared to similar cheese block products made byconventional processes. The relative improvement in moisture variabilityis at least about 50 percent, preferably at least about 75 percent, andmost preferably at least about 90 percent.

This controlled cooling process is especially useful in the productionof hard cheeses, such as Cheddar, Monterey Jack, or Colby cheeses. Theprocess can be used to provide low moisture variability in cheese blocksof a wide variety of shapes, including cheese blocks havingsubstantially symmetrical cross-sectional shapes, such as square,rectangular, triangular, circular, and the like as well as irregularcross-sectional shapes. The form or container may have a cross-sectionalgeometry corresponding to that of the desired cheese product.

This controlled cooling process is also applicable to the manufacture ofreduced fat, high moisture content varieties of these and other hardcheeses. This process extends the capability of cheese manufacturingsystems to produce bulk cheese at higher total moisture with less strainon downstream whey and waste water processing, thereby providing costsavings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart describing a process for making cheese havingreduced moisture variability through its thickness according to anembodiment of this invention;

FIG. 2 is a perspective view of an arrangement of a form and a tube usedin the process described in FIG. 1 for making a rectangular block shapedcheese product;

FIG. 3 shows a cheese product made using the equipment illustrated inFIG. 2;

FIG. 4 is a perspective view of an arrangement of a form and a tube usedin the process described in FIG. 1 for making a barrel (annular) shapedcheese product;

FIG. 5 shows a cheese product made using the equipment illustrated inFIG. 3;

FIG. 6 is an exploded perspective view showing the block sampling planuse to measure moisture variation at different vertical and depthpositions of a cheese block made in accordance with an embodiment of thepresent invention and a control cheese product made in a conventionalmanner, as described in Example 1 hereinafter;

FIG. 7 is a plot showing moisture measurements at the side, middle, andcenter locations of a cheese block made in accordance with an embodimentof the present invention and a control cheese product made in aconventional manner, as described in Example 1 hereinafter;

FIG. 8 illustrates another embodiment wherein a plurality of coolingtubes are used to provide cooling to a plurality of locations within acheese block;

FIG. 9 provides a top view of two alternative patterns (A and B) for theplurality of cooling tubes inserted into the cheese block according tothe embodiment of FIG. 8;

FIG. 10 provides a side view of the cheese block and the plurality ofcooling tubes inserted into the cheese block according to the embodimentof FIG. 8;

FIG. 11 illustrates a cooling tube which can be used for injectingcooling medium into a cheese block; and

FIG. 12 is a schematic illustrating the intermediate temperature method(solid arrows) of this invention and comparing it to the conventionalcooling method (broken arrow).

FIG. 13 is a flow chart describing a general process for making cheesehaving reduced moisture variability through its thickness according toan intermediate temperature embodiment of this invention; and

FIG. 14 is a more detailed flow chart describing a process for makingcheese having reduced moisture variability through its thicknessaccording to another intermediate temperature embodiment of thisinvention.

Features, dimensions, and sizes depicted in the figures are illustrativeonly, and are not necessarily to scale.

DETAILED DESCRIPTION

Referring to FIG. 1, a process 100 is shown for making a block of cheesehaving reduced moisture variability through its thickness in accordancewith an injection embodiment of the invention. In step 101, a form orbulk container having a bottom and sidewalls, and a tube having a fillend and an opposite discharge end, are provided. In step 102, thedischarge end of the tube is positioned at an approximately centralaxial location of the container. In step 103, cheese curd is introducedinto the container, and the tube via its fill end. In step 104, achilled brine is introduced into the tube via its fill end to mix withcurd therein. In step 105, the tube is removed from the cheese curd inthe container. In step 106, the cheese curd is pressed into a curdblock. In step 107, the cheese block is then cooled, providing a cheeseblock having reduced moisture variability. Thereafter, in step 108, itis further processed in a conventional manner. For example, it may becured, providing a cheese block having reduced moisture variability. Thecooled cheese block may be packaged prior or after curing, and then,after curing, the block may be cut into smaller blocks or pieces orshredded, and then wrapped for commercial distribution.

Referring to FIG. 2, a form or container 200 for holding and moldingcheese curd is shown having sidewalls 201, 202, 203, 204 and a bottom205 which define a cavity 206. The container 200 is open-ended at thetop and includes moisture-sealing inner sidewalls (e.g., metal, plastic,or wood). The form or container 200 generally has a three-dimensionalinternal geometry corresponding to that of the desired cheese product. Afeed or injector tube 207 is inserted into the cavity 206. The tube isoriented generally coincident with the central longitudinal axis 220 ofthe container 200. In this manner, it is spaced a substantially equaldistance from each of the sidewalls 201, 202, 203, 204 of the container200. The tube 207 has a fill end 208 and an opposite discharge end 209which preferably is positioned to rest (flush) on the bottom 205 of theform 200. The discharge end 209 generally is located at a central axialposition of the bottom of the container 205. Cheese curd is introducedinto the container cavity 206 as indicated by arrow 210 and inside thetube 207 as indicated by arrow 211 to fill each of the container 200 andtube 207. The tube preferably is filled with curd to the same height asthe cavity area of the form outside the tube. For example, the curd maybe discharged from a cyclone separator through its outlet end into thecontainer and the tube.

Then, a chilled brine solution is introduced into the tube 207 asindicated by arrow 212. The brine solution flows downward through theinterstices in the cheese curd inside the tube 207 under gravity flow.Within several minutes (e.g., 1-2 minutes) of introducing the brinesolution, the tube 207 is removed from the cheese curd in the container.The tube 207 preferably is removed from the cheese curd by raising thetube, approximately vertically (i.e., approximately parallel to axis220), out of the container, in order to help ensure that the brinesolution is left in the central axial region of the cheese curd mass asthe tube is extracted. The tube 207 may be manually or mechanicallylifted out of the container 200. If the curd is particularly firm, amechanical devise may be used to remove the tube from the barrel orblock. In an alternative embodiment multiple tubes may be inserted inthe central axial region of the container into which cheese curd and/orbrine solution my be introduced therein.

The chilled brine solution preferably is introduced into the tube 207positioned within the container 200 as an aqueous salt (NaCl) solutionat about 25 to about 30° F. having a salt content which is approximatelythe same as the salt content in the moisture phase of the cheese curd.In one particular embodiment, the cheese curd has a salt content ofabout 4 to about 6 percent into which the brine solution is introducedas about 4 to about 6 percent salt solution at about 25 to about 30° F.,and more particularly as about 4.5 to about 5.5 percent salt solution atabout 25 to about 27° F. In one preferred embodiment, the brine solutionis introduced into the tube at a rate of about 10 to about 25 pounds ofthe 4-6 percent brine solution per 640 pounds of cheese curd, and morepreferably about 12 to about 15 pounds of the 4-6 percent brine solutionper 640 pounds of cheese curd.

Generally the cross sectional area of the tube is about 2.5 to about 25percent and more preferably about 5 to about 20 percent of the totalcross sectional area of the block. In the manufacture of rectangularcheese blocks weighing approximately 600-700 pounds, or barrel (annular)shaped cheese blocks weighing approximately 500-600 pounds, the tube 207generally may comprise a cross-sectional diameter of about 7 to about 9inches. Or if multiple tubes, the diameters of the individual tubesshould supply approximately the same cross-section area as the singletube of about 7 to about 9 inches. The tube 207 may comprise a unitaryself-supporting hollow member comprised of a wall material selected fromthe group consisting of polymer, metal, ceramic, and wood. For instance,the tube may be polyvinylchloride (PVC) or stainless steel construction.

After the brine solution is introduced into tube 207 and the tube islifted out of the container 200, the cheese curd can then be pressed orvacuum pressed into a block, cooled, cured, subdivided, and packaged inconventional manners. For instance, rectangular blocks of cheesetypically are allowed to drain during pressing, and then are plasticwrapped before subsequent processing. Suitable techniques for pressingthe cheese blocks include those conventionally known and used (e.g., seeU.S. Pat. No. 4,049,838, which is incorporated herein by reference).Barrel or annular shaped blocks of cheese typically are sealed beforeand during pressing. For cooling, the freshly pressed cheese curd blocktypically will be cooled from a temperature of about 85 to about 90° F.to temperature of about of about 32 to about 40° F. over a period ofabout 3 to about 10 days. The cheese may then be stored in a curingchamber under controlled conditions.

FIG. 3 shows a rectangular cheese block product 300 made using theprocess described in FIG. 1 with a form as illustrated in FIG. 2. Thecheese blocks may be subdivided into smaller blocks or pieces, orshredded. For example, the cheese blocks may be packaged after pressingand before cooling, and then can be rewrapped after any subdividingoperation is performed before or after curing.

FIG. 4 is a perspective view of an arrangement of a cylindrical form 400and tube 407 used in the process described in FIG. 1 for making a barrel(annular) shaped cheese product. The form or container 400 for holdingand molding cheese curd is shown having sidewalls 401 and a bottom 405which define a cavity 406. A feed tube 407 is inserted into the cavity406. The tube is oriented generally coincident with the centrallongitudinal axis 420 of the container 400. In this manner, it is spaceda substantially equal distance from the sidewall 401 of the container400. As indicated above, the tube 407 has a fill end 408 and an oppositedischarge end 409, the latter of which preferably rests on or near thebottom 405 of the form 400. The discharge end 409 generally is locatedat a central axial position 421 of the bottom 405 of the container 400.Cheese curd is introduced into the container cavity 406 as indicated byarrow 410 and inside the tube 407 as indicated by arrow 411 to fill eachof the container 400 and tube 407. The tube preferably is filled withcurd to the same height as the cavity area of the form outside the tube.Then, a chilled brine solution is introduced into the tube 407 asindicated by arrow 412. As indicated above, the brine solution flowsdownward through the interstices in the cheese curd inside the tube 407under gravity flow. Within several minutes (e.g., 1-2 minutes) ofintroducing the brine solution, the tube 407 is removed from the cheesecurd in the container. Similar to the prior discussion in regard to FIG.2, the cheese mass is then pressed, cooled, and cured and otherwiseprocessed in conventional manners. As indicated above, the barrel cheesetypically is handled somewhat differently from the rectangular blockcheese in that the barrel cheese is vacuum sealed in its plastic linerand fitted with the container top so as to be sealed at its exteriorsides during pressing, and thus is not allowed to drain during pressing,FIG. 5 shows a barrel (annular) cheese block product 500 made using theprocess described in FIG. 1 with a form as illustrated in FIG. 4.

The introduction of the chilled brine into the core of the cheese curdmass before pressing, cooling, and curing has been found to counteractand significantly reduce moisture gradients from arising through thethickness of the cheese block, and especially between the central regionand side regions of the cheese block.

In an alternative, but less preferred, injection embodiment, cheese curdmay be filled into a form or container before the tube is insertedinside the container. The tube is inserted into freshly barreled/blockedcheese already prefilled into the form. In this arrangement, the top lipof the tube preferably is rolled to provide a hand grip and the bottomedge of the tube is sharpened or beveled to facilitate insertion of thetube into the curd. Mechanical pressing of the tube into the prefilledcontainer may be required if the pressed cheese is very firm. Then thebrine is introduced as described above.

In any of the injection embodiments described above, more than onecooling tube can be used to provide the initial cooling. FIG. 8illustrates a cheese block 300 having a plurality (in this case 5)cooling tubes. FIG. 9 illustrates the top of cheese block 300 withvarious placements of the cooling tubes 800. FIG. 9A has five coolingtubes 800; FIG. 9B has nine such tubes 800. FIG. 10 provides a side viewof cheese block 300 having a cooling tube manifold 802 having coolingtubes or wands 800 which are supplied by feeder lines 804 from supplyline 808 using flow control value 808. A bracing structure 810(partially shown) is positioned over the cheese block 300 to hold andstabilize the cooling tube manifold 802 during use. The use of aplurality of cooling tubes allows additional control over the cooling ofthe cheese block and reduced moisture value variability throughout thecheese bock.

FIG. 11 illustrates a modified cooling tube or wane 812 having aplurality of outlet openings 816 (generally diameters less than about 1inch and preferably of about 0.5 to about 1 inch) through which thecooling medium can be introduced into the cheese block. The coolingmedium (gas or liquid) from supply tank 814 is supplied through supplyline 808 to the cooling tube 812 via flow supply value 803. Suitablegases for use with this type of cooling tube include, for example,nitrogen, air, and the like; generally, the cheese block is sufficientlyporous so that the gas escapes during subsequent processing steps. Thistype of cooling tube can be used in any of the embodiments discussedabove.

Although the injection method has been described in detail using thechilled brine method to initially the cool the central portion of thecheese block, other methods to provide this initial cooling can be used.Such methods can include, for example, introducing precooled curdmaterial or a mechanical cooling device (e.g., a tube or plate havingcirculating coolant) into the middle or central portion of the blockrather than the chilled brine solution.

Referring to FIG. 12, the intermediate temperature embodiment or processfor making a block of cheese having reduced moisture variability throughits thickness is illustrated and compared with the conventional cheeseblock cooling process. The inventive process is shown with solid arrowsand the conventional process with broken arrows. For both theconventional process and the inventive process, the form is filled withcurd at a temperature of X° F. (typically about 60 to about 90° F.depending on the specific cheese variety used) and then pressed orotherwise treated to form the desired cheese block. In the conventionalprocess, the cheese block is placed directly in the final cooler orfinal cooling room at a temperature of about 35 to about 40° F. forabout 10 days, after which it is moved into the storage cooler at about40 to about 45° F. In such a process, the variability of the moisturecontent throughout the cheese block can be significant (e.g., absolutedifferences of up to about 5 percent moisture have been observed betweenthe central and outer portions of cheese blocks).

In the inventive intermediate temperature process shown in FIG. 12, theform is filled with curd at a temperature of X° F. (typically about 60to about 90° F. and preferably about 60 to about 90° F. depending on thespecific cheese variety used) and then pressed or otherwise treated toform the desired cheese block. The cheese block is then placed in anintermediate cooler (i.e., a cooler having a temperature between that ofthe initial fill temperature and that of the final cooler) for about 2to about 5 days (preferably about 3 to 4 days). After intermediatecooling, the cheese block is placed in the final cooler at a temperatureof about 35 to about 40° F. for about 5 to about 8 days (preferablyabout 6 to 7 days) after which it is moved into the storage cooler atabout 40 to about 45° F. Typically, the temperature of the intermediatecooler is about (X−10) to about (X−40)° F. (preferably about (X−15) toabout (X−25)° F.), but at least about 10° F. (and preferably at leastabout 20° F.) above the final cooler temperature. Using such controlledcooling, the moisture variability of the cheese block can be reduced toless than an absolute difference of about 2 percent (and preferably lessthan about 1 percent. Generally, the total cooling period (i.e., the sumof time in the intermediate cooler and the time in the final cooler) issufficient to bring the temperature of the cheese block to less thanabout 45° F.; typically, the total cooling time will be about the sameas in the conventional process (i.e., about 10 days).

As FIGS. 13 and 14 illustrate, cheese curd is filled into an appropriateform at an initial temperature (about 60 to about 90° F. depending onthe specific cheese variety used), pressed to form a large cheese block,stored at an intermediate temperature (preferably about 50 to about 80°F. for about 2 to about 5 days and more preferably about 50 to about 70°F. for about 3 to about 4 days), and then stored at a final temperature(preferably about 35 to about 45° F. for about 8 to about 12 days andmore preferably about 8 to about 10 days) to obtain the desired cheeseblock have reduced moisture variability throughout the block.

If desired, the injection and intermediate temperature embodiments maybe combined in a single process. Thus, for example, a cheese curd blockmay be initially cooled by introducing a chilled brine solution, achilled cheese curd mixture, a chilled gas, or a cooling device having arecirculating coolant into one or more portion of the cheese curd blockand then cooling the resultant cheese block at an intermediatetemperature of about 10 to about 40° F. below the initial temperatureand at least about 10° F. above the final temperature for a firstcooling period of about 2 to about 5 days and then cooling the resultantcheese block at the final temperature of less than about 45° F. for asecond cooling period of about 5 to 7 days, wherein the initial coolingin combination with the first and the second cooling periods aresufficient to cool the final cheese block to less than about 45° F.

For any of the embodiments described above, the absolute value of thisreduced moisture variability will depend, at least in part, on theinitial temperature of the cheese curd from which the block is prepared.Generally, the lower the initial temperature of the cheese curd, thelower the absolute value of the reduced moisture variability. Forexample, if the cheese curd has an initial temperature of about 60° F.,the moisture content is expected to vary by about 1 percent or less (andpreferably less than about 0.5 percent) from a location at a geometriccenter and a side edge portion. If the cheese curd has an initialtemperature of about 90° F., the moisture content is expected to vary byabout 2 percent or less (and preferably less than about 1.25 percent)from a location at a geometric center and a side edge portion.Regardless of the initial temperature of the cheese curd, cheese blockproducts made by the process of this invention have reduced moisturevariability as well as improved uniformity in texture and/or othersensory properties between the central and side portions of the cheeseblock products as compared to similar cheese block products made byconventional processes. The relative improvement in moisture variabilityis at least about 50 percent, preferably at least about 75 percent, andmost preferably at least about 90 percent.

In this manner, cheese block products made by a process of thisinvention herein have improved uniformity in texture and/or othersensory properties between the central and side portions of the cheeseblock products. This process is especially useful in the production ofhard cheeses, such as Cheddar, Monterey Jack, or Colby cheeses. Forexample, the process may be used in the manufacture of approximately 640pound cheddar cheese blocks having dimensions of approximately 26×28×32inches or 22×28×28 inches (side×side×height), or approximately 540 poundbarrel (annular) cheddar cheese blocks having dimensions ofapproximately 26×32 inches (diameter×height). Of course, other sizedblocks or barrels or other shapes can be used if desired. The processcan be used to provide low moisture variability in cheese blocks of awide variety of shapes, including cheese blocks having substantiallysymmetrical cross-sectional shapes, such as square, rectangular,triangular, circular, and the like.

This process is also applicable to the manufacture of reduced fat, highmoisture content varieties of these and other hard cheeses. For example,the process is useful to significantly reduce moisture variation betweenthe side and central regions of reduced fat (e.g., minimum 34 percentfat solids), high moisture (e.g., 40-49 percent moisture) cheeses,including cheddar cheese. This process can thus extend the capability ofcheese manufacturing systems to produce bulk cheese at higher totalmoisture with less strain on downstream whey and waste water processing,thereby providing cost savings.

The Examples that follow are intended to illustrate, and not to limit,the invention. All percentages used herein are by weight, unlessotherwise indicated.

EXAMPLE 1

An experimental study was conducted to compare the moisture variabilityin a cheddar cheese block (“inventive”) made with brine core coolingprior to pressing, cooling, and post-processing, in accordance with theinjection embodiment of the present invention, with a control cheeseblock (“control”) made in a conventional manner without the core coolingstep.

A block of cheddar cheese (22×28×28 inches (side×side×height)) wasmanufactured by filling a form having internal dimensions suited toprovide the desired product size with salted cheddar curd made in aconventional manner. A stainless steel, thin walled cylinderapproximately 8 inch in diameter was positioned in the center of theform with its discharge end touching the axial central region of thebottom of the form. Approximately 640 pounds of cheese curd (67° F.) wasthen filled into the container and the inside of the tube. The tube wasfilled with curd to the same height as the cavity area of the formoutside the tube. After insertion of the tube, 12.5 pounds of chilledsalted water (5.0 percent salt) at a temperature of 26° F. was pouredinto the center of the tube. Within 1-2 minutes, the tube was liftedvertically upward and out of the form.

The cheese was then treated in a normal manner. It was pressed, cooleddown to 36° F. over a period of about 72 hours, and then the moisturecontent was measured at different locations within the mass of thecheese block. A control cheese block was prepared in a similar mannerexcept without the brine core cooling step. After the 72 hour coolingstep, the moisture content of each block was measured at differentlocations within the mass of the cheese block 300 using the samplingscheme shown in FIG. 6, wherein sampling points were at variouscross-section depths and vertical height positions within the cheeseblocks. As indicated, 11 inch sample plugs 600 were withdrawn from thecheese block in the short side (22 inch) direction of the block at threedifferent vertical heights of the block: 602 (top), 604 (middle), and606 (bottom) using an appropriate corning device; plugs 600 were removedfrom the cheese block 300 as indicated by arrow 610. Each cheese plugtaken had three designated depth sections, indicated as sections A, B,and C in FIG. 6, which were each about 3.67 inches long, with section Aencompassing the exterior side of the block, section C encompassing acentral axial part of the block, and section B the intervening middlesection. The three different vertical height positions at which sampleswere extracted were at 29 inches from the bottom, 15 inches from thebottom, and 1 inch from the bottom (locations 602, 604, and 606,respectively).

Table 1 describes moisture content values measured after the coolingstep at the various sampling locations for the inventive cheese blockrepresenting and present invention and the control cheese blockrepresenting the prior art. The averages of the top, middle, and bottomsampling locations for each sampling depth location A, B, and C, as wellas the net differences of the averages are indicated in Table 1.

TABLE 1 Moisture (%) Moisture (%) Inventive A B C Control A B C Top50.27 50.27 49.95 Top 48.81 48.73 48.71 Middle 49.58 49.23 49.28 Middle50.37 49.27 48.51 Bottom 49.02 49.16 49.33 Bottom 50.05 50.02 48.71Average 49.62 49.55 49.52 Average 49.74 49.34 48.64 Average Net 0.10Average Net 1.10 Difference Difference

FIG. 7 is a plot of the average values of the top, middle, and bottommoisture measurements for the inventive sample and the control sample.As shown by the plot, moisture variation between the center and side ofthe inventive sample was limited to 0.10 percent, while the controlsample had a variation of 1.10 percent.

EXAMPLE 2

A similar cheese block was prepared using the injection embodiment as inExample 1 except that two 8-inch diameter PVC tubes were used tointroduce the chilled brine solution. The initial temperature of thecheese curd used to fill the container was 67° F. The temperatures ofthe outer and central portions of the cheese cured after introduction ofthe chilled brine were measured and the following results were obtained.

Temperature (° F.) Time Outer Portion Central Portion After FillingContainer with 67 67 Cheese Curd After Introduction of 67 50.5 ChilledBrine After Pressing to Form 67 62 Cheese Block* *Approximately 10 to 12minutes after introduction of chilled brine.The moisture variability of the resulting cured cheese block was similarto that found in Example 1.

EXAMPLE 3

A similar cheese block was prepared using the injection embodiment as inExample 1 except that (1) the initial temperature of the curd used tofill the container was at 80° F. and (2) the amount of chilled brineadded was varied. The conditions and results were as follows:

Moisture Difference Chilled Brine Curd Temp (° F.) Moisture^(†) RelativeAmount Temp. At At At Edge* At Center* Absolute Reduction Sample (lbs)(° F.) Initial Fill Center^(‡) (%) (%) (%) (%) Control 1 0 — 80 — 46.1243.25 3.87 — Inventive 1 8.6 27 80 64 43.87 42.73 1.14 70.5 Control 2 0— 80 — 46.65 43.35 3.3 — Inventive 2 12.9 27 80 56 43.95 44.42 0.47 85.7^(†)Measured after 10 days in cooler (temperature at 35-40° F.).^(‡)Measured within a few minutes of adding chilled brine. *Measured ata depth of 12 inches.

EXAMPLE 4

This example illustrates the intermediate temperature embodiment of thepresent invention. Several large cheese blocks (about 640 pounds; targetmoisture of about 48 percent and target fat of about 21 percent) wereformed using 2 percent milk cheddar curd at an initial temperature of70° F. A control bock was placed in the final cooler at a temperature of38° F. for 10 days. Inventive block 1 was placed in the intermediatecooler at an intermediate temperature of 56° F. for 3 days and thenplaced in the final cooler at a temperature of 38° F. for 7 days;inventive block 2 was placed in the intermediate cooler at anintermediate temperature of 56° F. for 4 days and then placed in thefinal cooler at a temperature of 38° F. for 6 days. After 10 total dayscooling, samples were taken from the center of the block, bottom corner,and top corner of each block and analyzed for moisture content. Thefollowing results were obtained.

Moisture (%) Moisture Difference (%) Bottom Top Bottom Corner Top CornerCorner Core Corner to Core to Core Control 48.5 44.4 47.9 4.1 3.5Inventive 1 47.2 45.6 43.9 1.6 1.7 Inventive 2 46.9 45.4 44.6 1.5 0.8The moisture difference is calculated as the absolute value of themoisture content of the corner (bottom or top) sample minus the moisturecontent of the core sample.

EXAMPLE 5

Example 4 was repeated and the following results were obtained.

Moisture (%) Moisture Difference (%) Bottom Top Bottom Corner Top CornerCorner Core Corner to Core to Core Control 48.7 46.8 49.1 2.1 2.3Inventive 1 46.9 46.3 45.8 0.7 0.5 Inventive 2 45.7 44.8 44.1 0.9 0.7

EXAMPLE 6

Example 4 was repeated except that the cheese curd was a high moistureMonterey Jack marbled cheese curd and a block fill temperature of 78° F.The final product had a moisture target of 47 percent and a fat targetof 26.5 percent. The following results were obtained.

Moisture (%) Moisture Difference (%) Bottom Top Bottom Corner Top CornerCorner Core Corner to Core to Core Control 47.3 42.4 45.7 4.9 3.3Inventive 1 46.0 44.7 43.7 1.3 1.0 Inventive 2 45.2 43.7 42.0 1.5 1.7

EXAMPLE 7

This example also illustrates the intermediate temperature embodiment ofthe present invention Several large cheese blocks (about 640 pounds;target moisture of 43 percent and target fat of 28.5 percent) wereformed using Monterey Jack curd at an initial temperature of 88° F.Control bocks were placed in the final cooler at a temperature of 38° F.for 10 days. Inventive block 1 was placed in the intermediate cooler atan intermediate temperature of 56° F. for 3 days and then placed in thefinal cooler at a temperature of 38° F. for 7 days; inventive block 2was placed in the intermediate cooler at an intermediate temperature of56° F. for 4 days and then placed in the final cooler at a temperatureof 38° F. for 6 days. After 10 days cooling, samples were taken from thecenter core, bottom corner, and top corner of each block and analyzedfor moisture content. The following results were obtained.

Moisture (%) Moisture Difference (%) Bottom Top Bottom Corner Top CornerCorner Core Corner to Core to Core Control 1 44.4 40.9 44.2 3.5 3.3Control 2 43.8 40.1 44.7 3.7 4.6 Inventive 1 42.2 40.9 41.8 1.3 0.9Inventive 2 42.9 41.1 42.4 1.8 1.3

While the invention has been particularly described with specificreference to particular process and product embodiments, it will beappreciated that various alterations, modifications, and adaptions maybe based on the present disclosure, and are intended to be within thespirit and scope of the present invention as defined by the followingclaims.

1. A process for making a block of cheese having reduced moisturevariability, said process comprising providing a bulk container having abottom and sidewalls; introducing cheese curd having an initialtemperature of about 60 to 90° F. into the container to form a cheesecurd block; pressing the cheese curd block to form a cheese block;controlled cooling of the cheese curd block or cheese block to a finaltemperature of less than 45° F. over a total period of about 7 to about13 days to form a final cheese block, wherein the controlled cooling iseffective to provide a reduced moisture content variation between ageometric center and side edges of the final cheese block as compared toa similar cheese block cooled directly to 45° F. over the total periodand wherein the final cheese block has a weight of at least about 500pounds, wherein the controlled cooling comprises first cooling at leastone portion of the cheese curd block in the container to a temperatureabout 10 to about 45° F. below the initial temperature and then coolingthe cheese block prepared therefrom to the final temperature to form thefinal cheese block; and wherein the cooling of the at least one portionis effected by introducing a chilled brine solution, a chilled cheesecurd mixture, a chilled gas, or a cooling device having a recirculatingcoolant into the at least one portion of the cheese curd block.
 2. Theprocess of claim 1, wherein a plurality of portions within the cheesecurd block are cooled to about 10 to about 45° F. below the initialtemperature and wherein the cooling of the plurality of additionalportions is effected by introducing the chilled brine solution, thechilled cheese curd mixture, the chilled gas, or a plurality of coolingdevices having the recirculating coolant into the plurality ofadditional portions of the cheese block.
 3. The process of claim 1,wherein the at least one portion of the cheese curd block is cooled to atemperature about 20 to about 45° F. below the initial temperature. 4.The process of claim 2, wherein the plurality of portions of the cheesecurd block are cooled to a temperature about 20 to about 45° F. belowthe initial temperature.
 5. The process of claim 1, wherein the cheeseblock has a diameter of about 24 to about 30 inches, and the cheeseblock has a moisture content variation of no greater than 2.0 percentbetween a location at a geometric center thereof and a side edgeportion.
 6. The process of claim 5, wherein the moisture contentvariation is no more than 1.0 percent between the location at thegeometric center and the side edge portion thereof.
 7. The process ofclaim 5, wherein the moisture content variation is no more than 0.5percent between the location at the geometric center and the side edgeportion thereof.
 8. The process of claim 2, wherein the cheese block hasa diameter of about 24 to about 30 inches, and the cheese block has amoisture content variation of no greater than 2.0 percent between alocation at a geometric center thereof and a side edge portion.
 9. Theprocess of claim 8, wherein the moisture content variation is no morethan 1.0 percent between the location at the geometric center and theside edge portion thereof.
 10. The process of claim 8, wherein themoisture content variation is no more than 0.5 percent between thelocation at the geometric center and the side edge portion thereof. 11.The process of claim 1, wherein the final cheese block has asubstantially symmetrical cross-sectional shape selected from the groupconsisting of square, rectangular, triangular, and circular and whereinthe final cheese block is a cheese selected from the group consisting ofCheddar, Monterey Jack, and Colby.
 12. The process of claim 2, whereinthe final cheese block has a substantially symmetrical cross-sectionalshape selected from the group consisting of square, rectangular,triangular, and circular and wherein the final cheese block is a cheeseselected from the group consisting of Cheddar, Monterey Jack, and Colby.